Magnetic field sensors are widely applied to modern industrial and electronic products to sense magnetic field intensity in order to measure physical parameters such as current, position, and direction. In the prior art, there are many different types of sensors which are used for measuring magnetic fields and other parameters, such as magnetic field sensors using Hall elements, Anisotropic Magneto resistance (AMR) elements or Giant Magneto resistance (GMR) elements as sense elements. Although Hall magnetic field sensors can work in high-intensity magnetic fields, they have the disadvantages of very low sensitivity, high power consumption, and the like. Although AMR magnetic field sensors are more sensitive than the Hall sensors, the AMR magnetic field sensors have a complex in manufacturing process, high power consumption, and are not applicable to high-intensity magnetic fields. Although GMR magnetic field sensors have higher sensitivity than the Hall magnetic field sensors, the GMR magnetic field sensors have low linearity range and are not applicable to high-intensity magnetic fields, either.
TMR (Tunneling Magneto Resistance) magnetic field sensors are new magnetoresistance effect sensors which have begun to be industrially applied in recent years, utilizing a tunneling magnetoresistance effect of a magnetic multilayer film material to sense magnetic fields, and they have higher sensitivity, and lower power consumption, than the Hall magnetic field sensors, the AMR magnetic field sensors and the GMR magnetic field sensors. However, the existing TMR magnetic field sensors are still not applicable to high-intensity magnetic fields and the linear range is not wide enough.